On 03/13/2014 11:08 AM, H. Peter Anvin wrote:
> On 03/13/2014 10:28 AM, Andy Lutomirski wrote:
>>
>> Does this mean you prefer the relocation approach to the compat vdso
>> removal approach? It seems like Linus is okay with either one.
>>
>
> Actually, thinking about it, removing it is probably better:
>
> a) gets rid of legacy code, making room for unification;
> b) either way enabling compat support (either relocation or disabling
> the vdso) has a performance penalty for *all* processes.
>
> The only way to avoid that is to have a vdso at a fixed addresses across
> all processes, either in the fixmap or in the user area (presumably at
> the very top.)
>
So going back and re-reading all the threads, the consensus was to
remove the compat vdso, but recycling the CONFIG_COMPAT_VDSO
configuration option name for the default-disable option.
It is important that anyone who actually cares about performance unsets
the option.
-hpa
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
